Oxycodone formulations are sometimes the subject of abuse. A particular dose of oxycodone may be more potent when administered parenterally as compared to the same dose administered orally. One mode of abuse of oral oxycodone formulations involves putting the active agent in solution and injecting it. Opioid antagonists have been combined with certain opioid agonists in order to deter the parenteral abuse of these drugs.
In the prior art, the combination of immediate release pentazocine and naloxone has been utilized in tablets available in the United States, commercially available as Talwin®Nx from Sanofi-Winthrop. Talwin®Nx contains immediate release pentazocine hydrochloride equivalent to 50 mg base and naloxone hydrochloride equivalent to 0.5 mg base. A fixed combination therapy comprising tilidine (50 mg) and naloxone (4 mg) has been available in Germany for the management of pain since 1978 (Valoron®N, Goedecke). A fixed combination of buprenorphine and naloxone was introduced in 1991 in New Zealand (Temgesic®Nx, Reckitt & Colman) for the treatment of pain.
Purdue Pharma L.P currently has marketed sustained-release oxycodone in dosage forms containing 10, 20, 40, 80 and 160 mg oxycodone hydrochloride under the tradename OxyContin®.
U.S. Pat. Nos. 5,266,331; 5,508,042; 5,549,912 and 5,656,295 disclose sustained release oxycodone formulations.
U.S. Pat. Nos. 4,769,372 and 4,785,000 to Kreek purport to describe methods of treating patients suffering from chronic pain or chronic cough without provoking intestinal dysmotility by administering 1 to 2 dosage units comprising from about 1.5 to about 100 mg of opioid analgesic or antitussive and from about 1 to about 18 mg of an opioid antagonist having little to no systemic antagonist activity when administered orally, from 1 to 5 times daily.
U.S. Pat. No. 5,472,943 to Crain et al. purports to describe methods of enhancing the analgesic potency of bimodally acting opioid agonists by administering the agonist with an opioid antagonist.
U.S. Pat. No. 3,773,955 purports to describe immediate release formulations comprising opioid agonists in combination with 0.1 to 2.5 mg naloxone.
All documents cited herein, including the foregoing are incorporated by reference in their entireties for all purposes.